Renal Flashcards
Where is calcium absorbed in kidneys?
The renal tubules
How much of the filtered calcium from the glomerulus will be reabsorbed by renal tubules?
95%
Where in the body is the largest calcium stores?
The skeleton
What three components control calcium haemostasis?
Vitamin D
Parathyroid hormone
Calcitonin
Where is calcitonin produced?
Secreted by the C cells of the thyroid
How does calcitonin affect calcium levels?
it inhibits calcium reabsorption in the renal tubules and inhibits calcium absorption in the intestine
Therefore lowering serum calcium levelsd
How does calcitonin affect osteoclast activity?
It inhibits osteoclast activity
What impact does the parathyroid hormone affect calcium and phosphate levels?
Increases serum calcium levels
Decreases phosphate levels
What is the active form of vitamin D?
1,25-dihydroxycholcalciferol
What is the half life of PTH?
10 minutes (very important to know for parathyroidectomy patients)
What is singularly the most important urinary buffer?
Phosphate
How much of the resting cardiac output do the kidneys typically recieve?
25%
What is the typical glomerular filtration rate?
125ml per minute
Define the glomerular filtration rate:
This it the total volume of plasma per unit of time that leaves the capillaries and enters the Bowman’s capsule
Define renal clearance:
The volume of plasma from which a substance is removed by the kidneys per minute